I just jumped into this python course. I may have missed it, but my question is:
Does Solo Learn have documentation for the programming languages they offer courses on? I was just thinking "do I have to leave the app to find a full set of rules on what is defined as a float? Decimals or non-whole numbers can't be it, right"
There is not such thing a perfect. Of course you have to use multiple apps to learn about something, SoloLearn only teaches the basics, everything else you have to learn for yourself throught searching and doing projetcs.
The tutorials here are basic, they make no attempt at telling you everything.
The side dishes you find here and the challenges fill it up a bit, but it's still far from all.
For getting an impression for only the core of Python, browse through the documentation linked down there.
Doesn't mean you have to (or will ever) know it all.